I got a LAN now and i want to play a mission together with my friend on the other pc, is that possible? otherwise i always have to play 1 vs 1 and i want to play with some computer figures.
No, you can't do that. There are no computer players (sometimes called "Bots") for MOHAA multiplayer games.
Zone
There are none ONLY because nobody has written a map WITH AI players...until now that is. Hiwayman (V2v2 and communcations author) has made a version of communications map that has AI players....But they shoot at BOTH teams.